Field of the Invention
The present invention relates to a lens apparatus, and more particularly, to a lens apparatus which a driving apparatus configured to drive a lens is mountable to and dismountable from, and to an image pickup apparatus including the lens apparatus.
Description of the Related Art
In general, a driving apparatus is mounted to a lens configured to take moving images for professional use. The driving apparatus is capable of driving a variety of operation of the lens in order to smoothly take a shot at a fixed angle of view or with zooming at ultra-low speed, which is difficult to achieve by manual operation. However, in recent years, the lens has been used in various ways as in cinematography using the lens independently. Accordingly, there is an increasing demand for a lens driving apparatus having the structure usable in a dismountable manner as well as the structure usable in a state of being fixed to the lens. As the structure in which the driving apparatus is mountable to and dismountable from the lens, the following structure is disclosed.
For example, Japanese Patent Application Laid-Open No. H08-9207 discloses a lens apparatus including a drive unit serving as a driving apparatus capable of adjusting light intensity through operation of a zoom ring and an iris ring of the lens, and a mountable and dismountable drive unit capable of adjusting a focus through operation of a focus ring of the lens.
However, in view of a recent demand for downsizing of machinery, in order to transfer power supplied to the driving apparatus and outputs from various types of detecting systems associated with operation of the lens, it is necessary to establish direct communication between the lens and the driving apparatus as a way of providing communication between the lens and the driving apparatus. In the lens apparatus disclosed in Japanese Patent Application Laid-Open No. H08-9207, the mountable and dismountable driving apparatus cannot establish direct information communication to the lens, and power needs to be supplied from an outside of the lens apparatus. As a result, it is difficult to downsize the lens apparatus.
Further, in general, as the structure for establishing direct communication between the lens and the driving apparatus, there has been known such structure illustrated in FIGS. 6A and 6B that a lens 1 and a driving apparatus 2 are connected to each other through a cable 3. As illustrated in FIG. 6A, in this structure, the driving apparatus 2 is fixed to the lens 1 by threadingly fitting screws (not shown) into fastening units 4. Further, in order to establish information communication between the lens 1 and the driving apparatus 2, the driving apparatus 2 is connected to the lens 1 through the cable 3. When a user uses the lens apparatus, it is necessary to protect the cable 3 exposed to the outside, and hence a protecting member 5 illustrated in FIG. 6B is fixed to the lens 1 with screws (not shown). Therefore, in order to dismount the driving apparatus 2 fixed to the lens 1, the screws (not shown) that fix the protecting member 5 are unfastened, and then the cable 3 is disconnected from the lens 1. Subsequently, the screws (not shown) fitted into the fastening units 4 are unfastened. Thus, the driving apparatus 2 can be dismounted from the lens 1. However, in a case of this structure, there are a large number of processes of mounting and dismounting the driving apparatus 2, and there is a risk of breaking of a wire when disconnecting the cable 3. Accordingly, a user cannot easily mount and dismount the driving apparatus 2.
Accordingly, as structure for establishing direct communication between the lens 1 and the driving apparatus 2 without using the cable 3, such structure illustrated in FIGS. 7, 8A, and 8B can be exemplified that communication between a lens 6 and a driving apparatus 7 is established through contacts 8a, 9a. In this structure, the driving apparatus 7 is fixed to the lens 6 by threadingly fitting screws (not shown) into fastening units 10. Further, in order to establish direct communication between the lens 6 and the driving apparatus 7, communication units 8, 9 are provided. As illustrated in FIG. 8B, the communication units 8, 9 can provide information communication and power supply to the driving apparatus in such a manner that the contacts 8a on the lens 6 side and the contacts 9a on the driving apparatus 7 side are brought into contact with each other. In addition, when a user dismounts the driving apparatus 7 from the lens 6, the user unfastens the screws (not shown) fitted into the fastening units 10, to thereby be able to easily dismount the driving apparatus 7 from the lens 6. However, in a case where the driving apparatus 7 has the above-mentioned structure, when a user drops the driving apparatus 7 in a solitary use state as illustrated in FIG. 9, the communication unit 9 is liable to locally undergo application of load, which is disadvantageous for impact resistance. Further, in general, when a user takes an image, the driving apparatus 7 is supported by his/her hand, and a surface of an operation unit 11 is operated by a thumb. In this situation, in a case where the communication unit 9 is arranged on the surface of the operation unit 11 so as to be exposed, the thumb of the user hits against the exposed part at the time of operation, thereby deteriorating operability. In addition, the driving apparatus 7 has structure reduced in a shielding property, a static electricity resistance property, a dustproof property, and a dripproof property.